The present invention relates an electric installation for heating molten metals and/or salts, as well as solutions by direct heating of the bath by means of resistance heating elements dipped in the bath. The electric heating installations so far known, wherein the heat generated in the heating elements is transmitted directly to the bath, are provided with heating elements as, for instance in the Polish Pat. No. 81,320, in the shape of one or several partitions located preferably parallel to the electrodes situated either in the bottom or in the walls of the melting tank. The partitions are built preferably of a uniform plate of ceramic material and divide the melting bath into two or more parts, or they are built in the walls or bottom of the melting tank and at least their one surface is in contact with the metallic bath, or as in the Polish Pat. No. 106,380 said partitions are provided with heating elements shaped as a vessel situated in the furnace chamber and the current supply units are situated inside the vessel shaped as an electrode, preferably a graphite one and the molten metal adheres to the bottom and walls of the heating element.
The drawbacks of known electric heating installations is their limited range of application, mainly they are used for non-ferrous metals, a relatively low power carrying capacity and a short service-life of the heating elements as a result of the destructive effect of thermal stresses arising in heating elements, a poor utilization of heating elements surfaces due the variable submersion depth of the heating elements, short life of electrodes and current supplies to heating elements caused by direct influence of the charge and atmosphere in the installation as well as a very difficult start-up of the equipment from the cold state as a result of a rather poor contact of the heating elements with the solid charge.
The aim of this invention is to have the above mentioned drawbacks eliminated or their effects reduced.
This aim has been achieved, among others by the application of a suitable shape and manufacturing method of heating elements, by series or series-parallel and also double series connections of contact materials into the heating element circuit, and by increasing the electrically active area of heating elements in using contact materials.
The purpose of the invention is the heating of molten metals and/or salts and solutions as well as melting and maintaining metals, salts and solutions in molten state and also their superheating.